Another Thursday, another bit of bad news for multitaskers. We already know that talking on the phone makes you drive like Bruce Willis in Die Hard With A Vengeance, but new research shows that memory-related tasks—like comprehending this article—suffer in the hands of multitaskers.
Though not directly related to the distracted driving brouhaha, the latest bit of research published Thursday in Science sheds light on why texting while writing a paper or studying for a test may not be the best way to prepare. Sylvain Charron and Etienne Koechlin, both from Institut National de la Santé et de la Recherche Médicale, Paris, engaged participants in either one or two letter matching tasks. Those who performed one task at a time performed substantially better than those who switched between two. Brain waves the researchers recorded while participants parsed the tasks pointed to a division of labor in the medial frontal cortex, or the area of the brain that helps estimate possible rewards for taking certain actions.
When focused on a single task, both sides of the medial frontal cortex were engaged. But when the subjects split their attention between two tasks (one with a larger cash payout than the other), the area was divided in half. Reward size had little to do with which side took up which task. Rather, the first assigned elicited activity in left side of the dorsal anterior cingulate cortex, an area close to the medial frontal cortex, while the second task lit up the right side. Dividing the “reward” area of the brain may have hampered participants’ abilities to appraise which task would give them the largest reward. Furthermore, multitaskers had significantly slower reaction times and higher error rates than people performing a single task.
The ability to handle two things at one time can be a fantastic advantage in some situations and a serious liability in others. “Clearly, we all multitask all the time,” said Camelia Kuhnen, an assistant professor of finance who specializes in neuroeconomics.
But just because we can does not mean we’re good at it. “We are indeed limited in terms of working memory—how many pieces of novel information we can keep track of before we commit them to long term memory,” she said, “but [these limitations] only apply to novel pieces of information—like when you are told a new phone number and you try to remember it.”
“When working memory is not that relevant—for instance, while you’re engaged in playing a sport like soccer and you need to keep track of all options available for passing the ball or dribbling or making a shot for the goal—I think you can pursue more than two goals simultaneously” without much loss of performance, Kuhnen said.
Though the study adds another chapter to our understanding of multitasking, it does not contribute much to the distracted driving debate, she said. “We know people are significantly more prone to having a car accident if they’re using their phone while driving than if they are not.” But in this study, the memory-related tasks are very different from those encountered in daily driving, Kuhnen said.
Photo by robertjosiah.